摘要
为改善和提高汽车支架类零件常用的AZ91D镁合金表面耐蚀性能,采用两步法在其表面电沉积Ni-SiO_2复合镀层。设计了正交试验,以SiO_2质量分数和表面粗糙度作为评价指标,运用正交试验法确定了施镀工艺参数的影响主次顺序,并得到最优施镀工艺参数为:镀液中SiO_2颗粒质量浓度20 g/L、电流密度8 A/dm^2、超声波功率300 W、镀液温度55℃。结果表明:采用最优施镀工艺制备出Ni-SiO_2纳米复合镀层,其表面平整、致密,腐蚀均匀,腐蚀速率为65 g/(m^2·d),明显低于镁合金基体的96 g/(m^2·d)。Ni-SiO_2纳米复合镀层能够提供有效的表面防护,改善和提高镁合金耐蚀性能。
Ni-SiO2 composite coating was prepared on the surface of AZ91D magnesium alloy for automo- bile by using two-step method in order to improve the corrosion resistance of AZ91D magnesium alloy, which was applied for the support spare parts of automobile. Orthogonal experiment was designed, and the content of SiO2 and the surface roughness were regarded as evaluation indexes. The primary sequence of the impact of electroplating process parameters was determined by the method of orthogonal experiment analysis, and the optimum electroplating process parameters were as follows：SiO2 particle concentration in plating solution was 20 g/L, current density was 8 A/dm^2, ultrasound power was 300 W, plating solution temperature was 55 ℃. The results showed that Ni-SiO2 nano-composite coating obtained under the opti- mum electroplating process parameters had smooth and compact rate was 65 g/（ m^2·d）, which was significantly lower than the strate. Ni-SiO2 nano-composite coating can provide effective surface, uniform corrosion. The corrosion 96 g/（ m^2· d） of magnesium alloy sub- surface protection, improve the corrosion resistance of magnesium alloy.
出处
《电镀与精饰》
CAS
北大核心
2017年第11期15-19,32,共6页
Plating & Finishing
基金
南通市市级科技计划项目(MS12015088)
